W2019 (Semester 1)
Answers online:
ubccac.com/class/biol112/2019
Disclaimer: All of these questions were made by fellow UBC Students, and do not accurately
represent the difficulty and content that will be covered by the BIOL 112 final.
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,Unit 1: General Properties, Chemistry For Biology,
Macromolecules
1. You are in the lab examining some cells under a microscope, but are for some reason unsure
whether these cells are bacterial cells, plant cells, or eukaryotic cells. What visual cues or
cellular structures would allow you to determine which kind of cell you are examining?
2. a. What some factors limiting cell size? (ie. what are the consequences of having an
unfavourably large cell size?)
b. What are some strategies cells employ to combat these factors? Give examples of different
types of cells that apply these strategies.
3. What properties of water allow it to form hydrogen bonds/PD-PD bonds with the major
macromolecules (lipids, carbohydrates, nucleic acids, and proteins)?
4. Name the non-covalent interactions 1-4 between the phospholipids and water molecules.
5. a. List the four major types of macromolecules.
b. Identify the monomers of each macromolecule.
c. Identify how the directionality of each type of macromolecule is determined and the reason for
the directionality.
d. Identify the type of covalent bonds that link these monomers together to form each type of
macromolecule.
6. Look at your amino acid table and find isoleucine and valine. Consider the properties of the
R-groups of each amino acid.
a. What is the strongest non-covalent interaction between isoleucine and valine?
b. If valine is replaced by glutamic acid, does the interaction change and why?
c. Which of the two scenarios above gives the greatest stability if these amino acids are
part of a protein in water?
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, 7. a. What is the endosymbiotic theory?
b. What evidence supports the theory?
8. Use the following diagram to answer the questions below.
a. Which of the following bonds are polar?
b. Which of the following can interact with water?
c. When interacting with a water molecule, what type of bonds will form with each group?
d. List the groups and their interaction with water from most stable to least stable.
9. At equilibrium, do solutes stop moving across membranes?
Unit 1: Membranes and Proteins
1. In the lab, your supervisor asks you to carry out some experiments on a phospholipid collected
from the plasma membrane of a cell in another experiment. You are able to cleave the
phospholipid into three molecules, getting you three unknown fragments, “A”, “B”, and “C”.
a. You try to dissolve fragment A in water, but it doesn’t dissolve and separates out. You
notice the same behaviour from fragment C. Fragment A and C are similar sizes, but B is
not. What portion of the phospholipid are fragments A and C, and why?
b. You then try to dissolve fragment B in water, and it dissolves. What part of the
phospholipid was fragment B originally?
c. You successfully create a phospholipid by joining fragments B and C, in a ratio of 1:2
with no leftover fragments. You notice the melting point of this new phospholipid is lower
than the original phospholipid given to you by your supervisor. List two possible reasons
for this observation:
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